A generic dispensing device is described, for example, in DE 197 19 339 C1. In this dispensing device, the screw conveyor is guided in a cylindrical screw tube. The screw tube itself is completely filled with the product during the operation of the dispensing device so that by driving the screw conveyor, a specific conveyed amount of the product can be discharged at the end of the screw tube. In this dispensing device, it is furthermore provided that the screw tube itself is arranged in a forming tube. The forming tube serves the purpose of guiding the tubular film, which has been formed from a film web by means of a forming shoulder, towards the sealing jaws of the tubular bag machine in a manner corresponding to a predefined shape. At the end of the forming tube, the product conveyed by the screw conveyor can be filled into the open cross section of the tubular bag.
The outer cross section of the forming tube results from the shape of the tubular bag to be produced, respectively, so that the inner cross section of the forming tube has an upper limit resulting from the shape of the respective tubular bag. The conveying capacity of the screw conveyor is operatively determined by the inner cross section of the screw tube. In the generic dispensing devices, the screw tube must be plugged into the open cross section of the forming tube, resulting in the fact that also the inner cross section of the screw conveyor is limited by the shape of the tubular bag to be produced, respectively.
Since the forming tube and the screw tube each have to possess a specific mechanical stability, the wall thickness necessary for manufacturing the forming tube and the screw tube also has a minimum limit. In other words, this means that the wall thickness of the forming tube and of the screw tube cannot be arbitrarily decreased because otherwise the forming tube and/or the screw tube would become mechanically unstable. However, since the screw tube must be plugged into the forming tube, the maximally available open inner cross section is consequently constricted by the wall thickness of the material for manufacturing the forming tube and by the wall thickness of the material for manufacturing the screw tube. Thus, the conveying capacity of the known dispensing devices is significantly limited owing to the open maximal cross section constricted by the wall thickness of the forming tube and of the screw tube.